Optimal Effect-site Concentration of Remifentanil for Inhibiting Response to Laryngeal Mask Airway (LMA) Removal

Optimal Effect-site Concentration of Remifentanil for Inhibiting Response to Laryngeal Mask Airway (LMA) Removal During Emergence From Sevoflurane-remifentanil Anesthesia

This study was designed to determine the optimal dose of remifentanil that can prevent the complications associated with the removal of LMA without delaying emergence.

Patients were randomly assigned to one of four groups. All patients received a predetermined effect-site concentrations (Ce) of remifentanil by target-controlled infusion (TCI) according to their group assignments (R0, remifentanil Ce of 0 ng/ml; R0.5, remifentanil Ce of 0.5 ng/ml; R1.0, remifentanil Ce of 1.0 ng/ml; R1.5, remifentanil Ce of 1.5 ng/ml) from 10 minutes before the end of surgery to LMA removal. Airway complications (airway obstruction, desaturation, breath holding, and coughing), nausea, and vomiting were assessed during the emergence phase.

Inclusion Criteria:

• American Society of Anesthesiologists physical status 1 or 2
• undergoing lower extremity surgery under general anesthesia

Exclusion Criteria:

• suspected difficult airways
• respiratory disease (chronic obstructive pulmonary disease, upper respiratory infection)
• body mass index > 30 kg/m2
• allergies to the study drugs
• a history of gastric reflux